Major Egyptian goddess (4)

I believe the answer is:
isis
(Other definitions for isis that I've seen before include "River Thames at Oxford" , "The upper Thames" , "where one might take a punt" , "Oxford's second crew" , "Mrs Osiris" .)
I believe the answer is:
isis
(Other definitions for isis that I've seen before include "River Thames at Oxford" , "The upper Thames" , "where one might take a punt" , "Oxford's second crew" , "Mrs Osiris" .)